1. Field of the Invention
The present invention relates to a heat conduction member where a cylindrical ceramic body is covered with a metal pipe.
2. Description of Related Art
Heat can be used effectively by heat exchange from a high temperature fluid to a low temperature fluid. For example, there is a heat recovery technique of recovering heat from high temperature gas such as combustion exhaust gas of an engine or the like. As a gas/liquid heat exchanger, a fin-provided tube-shaped heat exchanger of an automobile radiator, an air-conditioning outdoor unit, or the like is general. However, for recovering heat from gas such as automobile exhaust gas, it is difficult to use a general metal heat exchanger at high temperature because it has poor heat resistance. Therefore, heat resistant metals and ceramic materials having heat resistance, thermal shock resistance, corrosion resistance, and the like are suitable. However, heat resistant metals have problems such as high costs, difficulty in processing, high weight because of high density, and low heat conduction.
Therefore, a heat recovery technique using a ceramic material has been developed. For example, there is a technique of performing heat exchange by the use of a cylindrical ceramic body. In this case, heat exchange is performed by allowing the first fluid to flow through the inside portion of the cylindrical ceramic body and the second fluid to flow through the outside portion. In the case of heat exchange using a cylindrical ceramic body between gas and liquid, it is necessary to shield the cylindrical ceramic body lest the cylindrical ceramic body should have liquid leakage to mix the two fluids together.
Patent Document 1 discloses a technique of recovering heat by integrating a ceramic honeycomb structure as a cylindrical ceramic body with a metal base material (metal pipe).